Banana fiber-reinforced low density polyethylene (LDPE) based unidirectional composites (40% fiber by weight) were manufactured by compression molding. Banana fibers were treated with 2-ethylhexyl acrylate (EHA) mixed with methanol (MeOH) under UV radiation. A series of solutions of different concentrations of EHA in methanol along with photoinitiator were prepared. Monomer concentration and radiation dose were optimized in terms of polymer loading and mechanical properties. Chemically-treated banana fiber-reinforced specimens yielded better mechanical properties compared to the untreated composites. For the improvement of the properties, optimized banana fibers were again treated with aqueous starch solution (3-7%, w/w) for 2-8 min. Composites made of 6% starch-treated banana fiber (5 min soaking time) showed the best mechanical properties. Scanning electron microscopy, water uptake and soil degradation test of the composites were also investigated. (C) Koninklijke Brill NV, Leiden, 2012